Yusuf Abdallah Usman, director-general of the National Commission for Museums and Monuments in Nigeria, said the 32 items were looted during the Benin Massacre of 1897 by a British expedition as spoils of war, the Daily Trust reported Thursday.
"Without mincing words, these artworks are heirloom of the great people of the Benin Kingdom and Nigeria generally," Usman said. "They form part of the history of the people. The gap created by this senseless exploitation is causing our people, untold anguish, discomfort and disillusionment."
The sculptures are comprised of 28 bronze pieces and six ivory, the Daily Trust reported.
"It is very saddening that the Museum of Fine Arts, Boston, [which] now claim[s] to be the new beneficiary of these works, indicate[s] that the donation met all legal standards," Usman said.
"One wonders what they mean by this. Are they working out of the UNESCO Conventions and other standard setting instruments?"